JPH07167089A - Blower - Google Patents

Abstract

PURPOSE:To produce a silent effect by the edge of a high stage surface in the vicinity of an air delivery hole and a blade and to reliably suppress the generation of noise by a method wherein the edge of a partition part of a case member is inclined in a direction in which the width of a recessed groove is gradually reduced. CONSTITUTION:The edge 117 of the partition part 113 of a first case member 11 being one of two case members of which the case of a blower consists is inclined in a direction in which the width of a recessed groove 111 is gradually reduced in the direction of an air suction hole 114. This constitution forms a slope 116, the depth of which is gradually decreased from the opening edge of an air delivery hole 115 toward the surface of a partition part 113, in the recessed groove 111 and on the air delivery hole 115 side. A fan 2 is rotated in a space, in which a support base body 21 is formed at a high stage surface, and a given silent effect is produced in a way that a fan 22 is incorporated in a case in such a manner that the fan is rotated in an annular space formed by the recessed groove 111 and a space formed by the partition part 113.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blower utilizing the gutter principle.

[0002]

2. Description of the Related Art As prior art documents relating to a blower based on the side groove principle, JP-B-45-5579, JP-B-55-56238, JP-B-57-55994, JP-B-55-17238, and JP-B-Sho No. 59-9759 and Japanese Patent Publication No. 62-33438. The air compression principle of this type of blower is, as is known in the above publications, the fan is rotated at high speed in the case, and the air between the blades is caused to flow out from the root of the blade to the tip direction by centrifugal force. An annular compressed air flow (ring flow) is formed in the annular space, and the sucked air is compressed and discharged by repeating the compression and expansion actions of sending out between the next blades.

As described above, the fan is rotated at a high speed in the case, and a ring flow is generated between the blades to perform multi-stage and continuous air compression and delivery with the number of stages corresponding to the number of blades. Therefore, it is easy to handle and a relatively high discharge pressure and suction force can be obtained. Moreover, it is possible to obtain a discharge pressure comparable to that of a multi-stage turbo blower with a single fan, and when using it for suction, there is no need for a water seal or oil seal like a vacuum pump, and an equivalent vacuum pressure is required. It has the advantages that pressure can be obtained easily and that the machine is small and lightweight and easy to handle. Because of these advantages, their applications are being significantly expanded. In particular, the advantage of maintenance-free has attracted attention, and replacement of vacuum pumps has increased in recent years, and it has come to be used in automatic looms, printing devices, bookbinding devices, banknote calculators, zip code reading devices, and the like.

[0004]

However, in order to generate a high wind pressure, for example, a fan having a large number of blades of 40 to 50 is rotated at a high speed in the case, so that it does not cause annoyance from the surface of the machine body or the air intake hole. It has a fatal problem that noise of frequency is generated. Of the frequency noises, the noise of audible frequency of 2000 to 4000Hz reduces the work efficiency of the worker, or becomes a noise pollution when leaking to the vicinity of the office. Various measures have been taken in the past to reduce such noise, but they are still insufficient.

An object of the present invention is to provide a blower that operates according to the gutter principle.

Another subject of the invention is the noise, in particular
An object of the present invention is to provide a blower capable of remarkably reducing noise at an audio frequency of 000 to 4000 Hz.

Another object of the present invention is to provide a blower capable of reliably suppressing noise by relatively simple means.

[0008]

In order to solve the above problems, a blower according to the present invention includes a case and a fan, the case including a first case member and a second case member. The first case member and the second case member have a concave groove and a high step surface on one surface side, the concave groove is formed in a substantially annular shape, and the high step surface is the concave The first case member is formed in a flat shape inside the groove and has a partition portion that cuts across the concave groove, and the first case member has an air suction hole and an air discharge hole on both sides of the partition portion. The air suction hole and the air discharge hole penetrate between the one surface side and the other surface side to open in the concave groove, and the edge of the partition portion on the air discharge hole side is the air The air is drawn in a direction in which the width of the partition portion seen between the suction hole and the air discharge hole is gradually reduced. Inclined toward the direction of the entry apertures,
The concave groove has an inclined surface on the side of the air discharge hole that is gradually shallowed from the opening edge of the air discharge hole toward the surface of the partition portion. The member and the second case member are coupled so that the recessed groove, the high step surface and the partition portion face each other and a space is formed inside, and the fan is
A support base and a large number of blades, the blade is provided upright on the outer peripheral surface of the support base with a space,
Built in the case, the support base rotates in a space formed between the high-level surfaces, and the blade rotates in a space formed by the concave groove and a space formed between the partition portions.

Preferably, in the second case member, the partition portion has an extension portion extended to an inner wall surface surrounding the recessed groove, and an edge of the extension portion gradually extends the width of the extension portion. It is inclined in the direction of contraction.

[0010]

The first case member and the second case member have the concave groove and the high step surface on one surface side, and the concave groove is formed in an annular shape.
The high step surface is formed flat inside the concave groove, and has one partition part that blocks the concave groove, and the first case member is provided on both sides of the partition part on one surface side and the other surface side. The first case member and the second case member are provided with an air intake hole and an air discharge hole penetrating between the groove and the high groove surface and the partition portion are opposed to each other. And a fan including a support base and a number of blades, the blades being provided upright on the outer peripheral surface of the support base with a space therebetween, Is rotated in the space formed between the high-level surfaces, so that the blade rotates in the space formed by the concave groove and the space formed between the partition portions, because it is incorporated in the case,
By rotating the fan at high speed in the case, the air between the blades is caused to flow out from the root of the blade to the tip direction by centrifugal force, and an annular compressed air flow (ring flow) is formed in the annular space formed by the concave groove in the case. At the same time, a blower that compresses and discharges the sucked air, that is, a blower that operates according to the gutter principle, is obtained by repeating the compression and expansion actions of sending out between the blades.

In a blower that operates on this side groove principle,
In the first case member, since the edge of the partition portion is inclined in the direction in which the width of the concave groove is gradually reduced toward the air suction hole, the height of the partition portion near the air discharge hole is increased. A blade rotating at a high speed with respect to the edge of the step surface crosses while gradually decreasing the crossing angle as when closing the scissors. For this reason, the siren effect due to the edge of the high step surface and the blade near the air discharge hole is reduced, and particularly noise in the audible frequency range of 2000 to 4000 Hz is reduced.

In addition, the first case member has the concave surface on the side of the air discharge hole, which is gradually inclined toward the surface of the partition portion from the opening edge of the air discharge hole. From, the compressed air is discharged to the air discharge hole along the inclined surface without stagnation. Therefore, the generation of noise is suppressed and the compression effect is increased. if,
If the area of the inclined surface is made to have the same depth as the other areas of the concave groove, the compressed air is suddenly discharged to the air discharge hole, which may cause noise such as explosion sound. is there.

In the second case member, the partition portion has an extension portion extended to the inner wall surface surrounding the recessed groove, and the edge of the extension portion is inclined in a direction in which the width of the extension portion is gradually reduced. . With such a structure, in the second case member, the siren effect by the edge of the extended portion extending from the partition portion and the blade is reduced, and noise is further reduced.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a partial sectional view of a blower according to the present invention,
FIG. 2 is a right side view of the blower shown in FIG. The blower according to the present invention includes a case 1 and a fan 2.
Reference numeral 3 is a motor, 4 is an air suction pipe, 5 is an air discharge pipe, and a is a rotation direction. The case 1 is the first case member 1
1 and the second case member 12 are included. 3 is a view with the second case member 12 removed along the line A3-A3 in FIG. 1, and FIG. 4 is a view with the fan 2 removed from FIG.
As shown in the figure, the first case member 11 has a concave groove 111 and a high step surface 112 on one surface side. The concave groove 111 is formed in an annular shape. The high step surface 112 is formed in a flat shape inside the concave groove 111, and has a partition portion 113 that cuts across the concave groove 111. First case member 1
1 includes an air suction hole 114 and an air discharge hole 115 that are formed on both sides of the partition portion 113 and that penetrate between the one surface side and the other surface side and open into the concave groove 111. Edge 11 of partition 113
7 is inclined in a direction in which the width of the concave groove 111 is gradually reduced toward the air intake hole 114. Groove 111
Has an inclined surface 116 provided on the air ejection hole 115 side so as to become gradually shallower from the opening edge of the air ejection hole 115 toward the surface of the partition portion 113.

The second case member 12 also has the concave groove 1 on one surface side.
21 and a high step surface 122. The concave groove 121 is formed in an annular shape, and the high step surface 122 is formed in a flat shape inside the concave groove 121, and has a partition portion 123 that cuts across the concave groove 121.

In the first case member 11 and the second case member 12, the concave grooves (111 and 121), the high step surfaces (112 and 122) and the partition portions (113 and 123) face each other, and To form a space.

The fan 2 is, as shown in FIGS. 3 and 8,
It includes a support base 21 and a number of blades 22. The blades 22 are provided upright on the outer peripheral surface of the support base 21 at intervals. The fan 2 is, as shown in FIG.
The support base 21 rotates in the space formed between the high-level surfaces 112-122, and the blade 22 rotates in the annular space formed by the concave grooves 111-121 and the space formed between the partition portions 113-123. It is incorporated in the case 1.

As shown in FIGS. 6 and 7, in the second case member 12, preferably, the partition portion 123 has the concave groove 12.
1 has an extension portion 125 extended to an inner wall surface 124. Both end edges 126 and 127 of the extension portion 125 are inclined in a direction in which the width of the extension portion 125 is gradually reduced.

As described above, the first case member 11 and the second case member 12 have the concave grooves 111, 121 on one surface side.
And high step surfaces 112 and 122, and the concave grooves 111 and 121.
Are formed in an annular shape, and the high-level surfaces 112 and 122 have the concave groove 11
1 and 121 are formed in a flat shape inside and the concave groove 1
The first case member 11 has partition parts 113 and 123 for blocking the parts 11 and 121, and the first case member 11 penetrates on both sides of the partition part 113 between the one surface side and the other surface side and opens into the concave groove 111. The first case member 11 and the second case member 12 are provided with air intake holes 114 and air discharge holes 115.
Are concave grooves (111 and 121) and high steps (112 and 12).
2) and the partition portions (113 and 123) are opposed to each other and are coupled so as to form a space inside, and the fan 2 has blades 22 spaced apart from the outer peripheral surface of the support base 21. The support base 21 is provided upright and rotates in the space formed between the high-level surfaces 112-122, and the blade 22 is formed between the annular space formed by the concave grooves 111-121 and the partition portions 113-123. Since it is installed in the case 1 so as to rotate in a space, a blower that operates according to the gutter principle can be obtained. The outline of operation of the blower based on the gutter principle is as follows.

When the fan 2 is rotated at a high speed in the direction of arrow a in the case 1, it passes through the air suction pipe 4 and passes through the air suction hole 1
The air sucked from 4 is guided to the annular space formed by the concave grooves 111 and 121. In the annular space, the air between the blades 22-22 is discharged from the root of the blade 22 toward the tip direction by the centrifugal force accompanying the high speed rotation, and the annular compressed air flow (in the annular space formed by the concave grooves 111 and 121 in the case 1 ( (Ring flow) is formed, and the compressed air is repeatedly sent out between the next blades 22-22, so that the sucked air is compressed, and the air is sucked from the air suction hole 114 side toward the air discharge hole 115. Pumped. In the vicinity of the air discharge hole 115, the partition portion 113,
Since 123 is provided, the partition portions 113, 1
At 23, the pressure feed is blocked and the air is discharged from the air discharge hole 115 to the outside. In the air discharge hole 115, for example, the air discharge pipe 5 with a silencer is arranged.

In the blower that operates on the side groove principle,
Since the edge 117 of the partition part 113 is inclined in the direction of gradually reducing the width of the concave groove 111 toward the air suction hole 114, the high step forming the partition part 113 near the air discharge hole 115. With respect to the edge of the surface 112, the blade 22 gradually crosses the crossing angle θ, as when closing the scissors.
(Refer to FIG. 3) to start rotating. Therefore, the edge 1 of the partition portion 113 near the air discharge hole 115
The siren effect by 17 and the blade 22 becomes small,
Noise is reduced.

Moreover, the first case member 11 has the concave groove 1
Since 11 has an inclined surface 116 provided on the air discharge hole 115 side so as to become gradually shallower from the opening edge of the air discharge hole 115 toward the surface of the partition portion 113, compressed air is trapped. Instead, the air is discharged to the air discharge hole 115 along the inclined surface 116. Therefore, the generation of noise is suppressed and the compression effect is increased. If the area of the inclined surface 116 is made to have the same depth as the other areas of the concave groove 111, the compressed air is suddenly discharged to the air discharge hole 115, so that noise such as an explosion sound is generated. Can occur.

As shown, the second case member 12
The partition portion 123 has an extension portion 125 extended to an inner wall surface 124 surrounding the recessed groove 121, and end edges 126 and 127 of the extension portion 125 are inclined in a direction in which the width of the extension portion 125 is gradually reduced. If so, the second case member 12
Also in the extension portion 125 extending from the partition portion 123
The siren effect of the edges 126 and 127 of the blades and the blade 22 is reduced, and noise is further reduced.

9 and 10 are graphs showing experimental data. In the figure, the horizontal axis represents the octave band center frequency (Hz), and the vertical axis represents the octave band sound pressure level (dB). FIG. 9 shows the data when the air suction pipe 4 is closed, and FIG. 10 shows the air discharge pipe 5.
This is the data when the deadline is closed. Data A1 and A2 are data of the blower according to the present invention (product of the present invention), data B
1 and B2 are data of a conventional blower (conventional product). As is clear from the experimental results, the blower according to the present invention has a sound pressure level lower than that of the conventional blower in almost the entire frequency range. In particular, the reduction in the audible frequency range of 2000 to 4000 Hz, which is a problem as noise, is remarkable.

The fan 1 is formed as a molded body of aluminum casting or the like, and the rotating shaft 31 of the motor 3 is attached and fixed to the central portion thereof and is rotated inside the case 2. A rib 23 is provided at an intermediate portion in the width direction between the blades 22 (see FIG. 1), whereby a double-blade blower is obtained. A single blade type in which one side is closed without the rib 23 as described above is also well known.

The case 2 is formed of a molded body such as aluminum casting, and is screwed or the like by closing the front surface of the first case member 11 integrally attached and fixed to the motor 3 by means of screwing or the like. Second case member 1 by means of
It is formed by combining two.

[0027]

As described above, the present invention has the following effects. (A) It is possible to provide a blower that operates according to the gutter principle. (B) It is possible to provide a blower capable of significantly reducing noise, particularly noise having an audible frequency of 2000 to 4000 Hz. (C) A blower capable of reliably suppressing noise can be provided by a relatively simple means.

[Brief description of drawings]

FIG. 1 is a front partial cross-sectional view of a blower according to the present invention.

FIG. 2 is a right side view of the blower shown in FIG.

FIG. 3 is a diagram showing the second case member removed along the line A3-A3 in FIG.

FIG. 4 is a view of FIG. 3 with a fan removed.

5 is a partial cross-sectional view taken along the line A5-A5 of FIG.

FIG. 6 is a plan view of a second case member.

FIG. 7 is a perspective view showing a part of a second case member.

FIG. 8 is a front view of the fan.

FIG. 9 is a graph showing experimental data.

FIG. 10 is a graph showing experimental data.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Case 11 1st case member 12 2nd case member 111 Recessed groove 112 High step surface 113 Partition part 116 Inclined surface 117 End edge 121 Recessed groove 122 High step surface 123 Partition part

Claims (2)

[Claims] 1. A blower including a case and a fan, wherein the case includes a first case member and a second case member, and the first case member and the second case. The member has a concave groove and a high step surface on one surface side, the concave groove is formed in a substantially annular shape, the high step surface is formed in a planar shape inside the concave groove, and the concave groove is formed. The first case member has an air intake hole and an air discharge hole on both sides of the partition part, and the air intake hole and the air discharge hole are on the one surface side. The other edge penetrates and opens in the concave groove, and the edge of the partition portion on the side of the air discharge hole,
In the direction of gradually reducing the width of the partition part seen between the air suction hole and the air discharge hole, the groove is inclined toward the direction of the air suction hole, and the concave groove is on the air discharge hole side, The first case member and the second case member each have an inclined surface that is gradually shallowed from an opening edge of the air discharge hole toward a surface of the partition portion. The groove, the high step surface and the partition portion face each other,
And, the fan is coupled so as to form a space therein, the fan includes a support base and a number of blades, the blades are provided upright on the outer peripheral surface of the support base with a space, A blower installed in the case, in which the support base rotates in a space formed between the high-level surfaces, and the blade rotates in a space formed by the concave groove and a space formed between the partition portions. . 2. The second case member has an extension portion in which the partition portion is extended to an inner wall surface surrounding the groove.
The blower according to claim 1, wherein an edge of the extension portion is inclined in a direction in which the width of the extension portion is gradually reduced.